Apparatus for corrugating paper in a direction parallel to the length of the sheet



Oct. 3, 1961 A G. RosATl 3,002,876

APPARATUS FOR CORRUGATING PAPER IN A DIRECTION PARALLEL TO THE LENGTH OF' THE SHEET Filed Oct. 18, 1956 4 Sheets-Sheet 1 F i 1/ ,15 l 1h lL-M331 1? Eigf 9 lNr/E'NTOR.

Oct. 3, 1961 G. RosATl 3,002,876

APPARATUS RoR coRRUGATTNG PAPER TN A DIRECTION PARALLEL. To THE LENGTH oF THE SHEET 4 Sheets-Sheet 2 Filed OCT.. 18, 1956 INVENTOR. G. /osac' BY @JNM/uw ATTOENESI Oct. 3, 1961 G. RosATl 3,002,876

APPARATUS FOR CORRUGATING PAPER IN A DIRECTION PARALLEL TO THE LENGTH OF THE SHEET Filed Oct. 18, 1956 4 Sheets-Sheet 5 [N VEN TOR. G. Rosa'lfr.'

oct. 3, 1961 G ROSA 3,002,876

APPARATUS FOR CORRUEATING PAPER IN A DIRECTION PARALLEL TO THE LENGTH OF' THE SHEET Filed Oct. 18, 1956 4 Sheetsl-Sheet 4 m o I w- QD O/ ze o Q NVENTOR.

GKOSCL 3,002,87 6 APPARATUS FOR CORRUGATING PAPER IN A DIRECTION PARALLEL T THE LENGTH 0F THE SHEET Gildo Rosati, Via Federico Cesi 30, Rome, Italy Filed Oct. 18, 1956, Ser. No. 616,714 Claims priority, application Italy Oct. 22, 1955 3 Claims. (Cl. 156-594) The present invention relates to an apparatus for corrugating paper in a lengthwise direction, i.e. parallel to the direction in which the paper unwinds from the roll. With paper corrugated in this fashion, laminated with paper corrugated in the usual fashion (crosswise to the sheet), interposing and/or adding sheets of plain paper, packaging board can be obtained which presents a high resistance to flexing in all directions.

The invention is based upon the principle of passing the sheet of paper to be corrugated, which unwinds from a roll, between organs capable of forming a first lengthwise corrugation on the centerline of the sheet, then progressively forming additional corrugations on the sides of` the centerline and parallel to it, till the entire width of the sheet is corrugated, the paper being gradually pulled in from the sides of the sheet.

This operation can be performed by mechanical or pneumatic means, as illustrated in detail in the description of certain embodiments of this invention, which are presented as non-limiting examples, with reference to the enclosed tables of drawings, in which:

FIG. 1 is a plan view of the lower part of a ball bench on which the corrugation process is performed;

FIG. 2 is a front view of some pairs of elements of the two superimposed tables which constitute the corrugating bench;

FIG. 3 is a side view of a belt-type corrugating machine; y

FIG. 4 is a plan view from the above of the same machine;

FIG. 5 is a front view, in partial cross-section along the plane Ill-III of FIG. 4, of the first pair of rollers;

FIG. 6 is a front view, in partial cross-section along the plane IV-IV of FIG. 4, of the second pair of rollers;

FIG. 7 is a partial cross-section of a pair of marching rollers, between which run belts of a preferred crosssection shape;

FIG. 8 is a prospect view of a device for corrugating paper by the action of compressed air, instead of by belts rolling between rollers, lfollowing the same basic principle;

lFlG. 9 shows the general arrangement of a device according to the invention, fitted in the line of machines for laminating with other corrugated papers and plain papers;

FIGJIO shows the general arrangement of aproduction line comprising corrugating machines according to the invention and corrugating machines of known type;

FIG. 11 shows two corrugated sheets glued together with the corrugations perpendicular to each other;

IFIG. l2 shows two corrugated sheets, with the corrugations perpendicular to each other, glued together With plain sheets.

With special reference to FIGS. l and 2, on an ideal plane comprised between two parallel groups of prismatic bars 1 and 2, there is inserted a sheet of paper, light cardboard or the like 3. The prsmatic bars of both the lower group 1 and the upper group 2 have a constant trapezoidal section, with the -wider base respectively resting upon and fastened to plates 4 and 5, and with the corners 6 and 7 of the wider bases adjacent to each other.

Appropriately spaced from each other, at equal intervals., in the lfase corresponding to the narrow ,base of the 3,662,876 Patented Oct. 3, 1961 ice two groups of prismatic bars, there are provided halfspherical cavities 9, into which is fitted a ball 10 having a radius substantially equal to that of the desired corrugation.

The prismatic bars 1 are arranged in lengths which decrease from the midline to the sides. The arrows A indicates the direction of feed of the paper which, before entering the machine described herein, has a width of x-l-y. Let us now imagine, superimposed to the bench shown in FIG. l, another bench entirely equal, but mounted in the staggered position shown in FIG. 2.

This second bench is formed by the prismatic bars 2, and the two benches are staggered by the half-width of one corrugation. Let us assume now that the paper 3, of the width x-t-y, is fed into the machine between the two benches of prismatic bars 2 and l, guided by the rubber-lined rollers 13. The rollers are mounted in pairs, and in FIG. l are shown in dotted lines, since they are located underneath the sheet of paper 3. The marching paper feed roller will be located above the said sheet of paper.

When the paper encounters the balls mounted on the longest of the bars 1, a first corrugation is formed in it along the lengthwise centerline. Consequently, the width of the paper decreases. As it can be clearly seen from FIG. l, as the paper is fed in, in the direction shown by the arrow A, there come into action the balls of the prismatic side bars which shape further corrugations in the sheet of paper, the Width of which becomes gradually reduced to the nal width x. The paper of reduced width comes into the field of action of other rollers 14, with their axis at an angle to the direction of the paper sheet feed to allow for the combined feeding and narrowing motion.

The balls do not oppose in any Way the gradual narrowing of the sheet of paper, because they are free to roll in all directions under the action of the changes in the motion of the paper.

At the end of the bench, when the paper has narrowed down to the width x, it passes between the grooved rollers l5 which, possibly in combination with the other pairs of guide and/ or feed rollers, pull the paper through the machine. These rollers *15, which are shown only in outline in the figure, match and set the shape assumed by the fibers of the corrugated paper.

With special reference to the FIGURES 3 through 6, the paper corrugating machine according to a different construction, is formed by two side frames A-A' and B-B, parallel and respectively upper and lower. These side frames carry the bearings for the shafts of the grooved rollers, which revolve freely therein, the said rollers having all the same diameter and being `all tangent to a horizontal plane marked by the arrow C (FIG. 3), which also indicates t-he `direction of feed of the paper between the rollers.

The rollers 21, 23, 25, 27 which form the upper gang lare superimposed to the rollers 22, 24, 26, 28 and their shafts yare parallel to those of the underlying rollers and placed on the same vertical plane.

Between the upper-gang `rollers and a power roller 41 mounted on the rear end of the machine run several parallel belts fitting in grooves of the rollers. These belts, as indicated below, increase in number towards the power roller, till they form a mat as the paper receives the progressively increasing number of corrugations.

The same thing happens with the lower gang of .rollers `and belts, which are driven by the power roller 42 which revolves at the same speed as power roller 4l. To this end, the power rollers 41 and 42, driven by the shaft 43, will be interconnected by means of a gear train, to prevent any angular slippage.

Based on the statements made in the preamble and on the principle ot this invention, the paper is corrugated starting from the centerline, so that the shrinkage of the sheet, which inevitably decreases in width, may freely take place from the sides towards the center.

In the case described here, since the corrugations are imparted by means of belts, which in the example shown in the drawing are of round cross-section, the first pair of rollers 21-22 (FIG. 5) will carry in the center the grooves required for shaping a lirst corrugation i.e. three grooves, because each groove is formed by one ridge and two half-throughs on the sides. Bearing in mind that the paper is fed into the space C (FIG. 5) between the two rollers 21 vand 22, the roller 22, will bear one belt but three grooves, because it must accommodate also the other two belts of the roller 21, which project half out of their section. For the same reason, also thel roller 21 will have three grooves.

With the following pair of rollers 23 and 24, it will be necessary to increase the width of the paper being corrugated. To this end, two new belts are added on the roller .24, and thus in the contact arca C there will pass three belts of the lower gang, `and since two new belts are added also to the roller 23, there will be four other belts of the upper gang. The grooves will therefore be seven,

because each roller, in addition to accommodating the belts passing `around it must allow a passage for those of the tangent pair, which project halfway out.

For the same reason, adding two new belts (one on each side) to the rollers of the third pair, 25-26, we will have tive belts on the lower roller 26 and six belts on the upper roller 25, and therefore we will have in the area C, i.e. in the point of tangence of the roller pairs, eleven belts `adjacent to each other.

It should be noted that all of the said belts, i.e. those mounted on the rollers 21-22 of the rst pair, and those subsequently added to the right and to the lett, are threaded from each roller of the upper gang to the power roller 41, and from each roller of the lower gang to the power roller 42.

FIG. 7 represents a pair of rollers 43-44 upon which are mounted belts having a special .cross-section shape specially suited to the corrugating of paper. The belt comprises a trapezoid-al section which fits into the corresponding roller groove, a tlat section 46 wide enough to form a continuous mat with the edge of the adjacent belt, and a shaped section 47 upon which the corrugation is formed.

The same result would be obtained if -all the belts were removed and the upper and lower gang of rollers were substituted by pairs of free wheels alternately fitted with projections and grooves having the same profile as the rollers in FIGS. 5 and 6.

One further `form of embodiment of the invention is represented in FIG. 8. A closed-end mat of rubber, plastic or similar material 51, which on the upper face presents the same corrugations to be shaped in the paper, runs on two cylinders 52 and 53, the former being freely rotating and the latter power-driven, making the mat ad Vance in the direction shown by the arrow.

A sheet of paper of the width x-l-y unwinds in the usual manner `from a roll not shown in the iigure. The sheet of paper is laid on the mat 51, pressed against the corrugations of the latter by the roller 57 and advances with the mat, passing underneath a gang of parallel pipes. The center pipe 55 is the longest of all, and other pipes are laid symmetrically and parallel to it-551, 553, 555 on the left and 552, 554, 556 on the right. The side pipes have symmetrically the same length for each pair, but they all grow gradually shorter from the center outwards.

The pipes are located facing the grooves in the mat 51 and at a short distance therefrom, so that they leave free passage to the sheet of paper without touching it, and on the lower side they have a narrow slit, either continuous or with small intervals. On the end facing the roller 52 the pipes are capped, while on the other end they are connected to a manifold pipe 56 from which they receive compressed air. The air, owing out of the slits referred to above, presses the paper into the grooves of the mat. This shaping of the paper starts at the front end of the longest pipe and continues progressively with the other pipes', the paper being drawn in from the right and left edges exactly in accordance with the principles underlying the mechanical arrangements described above. I-f the mat, by its own weight or under pressure of the air jets, tended to sag downwards, it could be supported from underneath.

It can be understood that the sheet of paper, running underneath the pipes in the conditions described above, will not be stressed in Iany way, and the rollers themselves willV have no resistance to overcome. It will be preferable to `feed conditioned air through the pipes and slits, so that when it leaves the mat, the corrugated paper is almost entirely dry, in the case it was -fed wet into the machine. A pair of rollers of x width, heated and corrugated lengthwise, placed beyond the mat, will bring the paper to the correct degree of moisture, setting the corrugations.

It is understood that special arrangements may be adopted to ensure the most etiicient operation of the machine. For instance air at different pressure can be fed into the pipe 5S, according to their position and length, while along the mat ilat guide rollers may be placed, not wider than the area of pape-r which has been corrugated immediately ahead of them.

It was said above that the advantage offered by this invention is that of. permitting two plain sheets of paper to be laminated with two sheets of paper corrugated at right angles, so as to obtain a cardboard having a high resistance in -all directions.

According to the invention, this is obtained by means oi the machine outlined in FIGURES 9 and l0. With reference to FIG. 9, the paper to be corrugated unwinds from the roll 60 of the width x-l-y, x being the width to be assumed by the paper after passing .through the machine.

From the roll the continuous sheet passes into a moistening device 6l, and from the latter into t-he apparatusl according to the invention, which may be of one of the types described and represented in the previous figures. In the case of the apparatus shown in FIGURES 3 and 4, the paper enters at C between the rollers 21, 23, 25and the rollers 22, 24, 26 land comes out of the last pair of rollers 41-42, where its width has become x for the reasons discussed above.

From the rollers 41--42 the corrugated paper passes between a pair of corrugated and heated rollers 63 which remove the remaining moisture and set the corrngations. After this pair, there is located, facing the lower corrugated surface of the paper, a plain (ungrooved) gluespreading roller '64, which spreads glue on the ridges o the corrugations. The corrugated paper then passes between a grooved conveyor mat 65 and a at conveyor mat 66 which, in turn, presses against the ridges of the corrugations a sheet of plain paper of the width x, which unwinds from the roll 67. Thus, from the mats 65 and 66 there will emerge a sheet of corrugated paper 63 glued to a plain sheet of paper, and the whole can be fed into other conventional machines for further combinations.

The sheet corrugated with any one of the machines described above may be combined with another sheet with the corrugations perpendicular to the direction of feed, by means 'of the apparatus represented in FIG. l0.

The lengthwise corrugated paper 68 passes between the grooved and heated rollers 69, which set the corrugation.

A roll 72 of the width x'unwinds paper which, after passing through a moistener 73 is fed tangentially between 'a pair of gears with special teeth 74 which corrugate thepaper perpendicularly to the direction ofl feed.

The corrugated paper passes to a support mat 75 corrugated perpendicularly to the direction of feed, and then to a heated roller 76 which removes the moisture and sets the corrugations, and further it reaches the lengthwise corrugated sheet 68, the ridges' of which have been glued by the roller 70.

The combined action of the conveyor 79 grooved in the direction of feed and of the conveyor mat 75 grooved perpendicularly to the direction of feed, results in the two sheets of paper being pressed against each other, so that the crossed corrugations contact by the respective ridges without distorting them, and since the sheet 68 is glued as indicated above, a two-layer cross-corrugated board 30 will be obtained, which can then be fed into a machine of known type for further processing into sandwiches of corrugated and plain paper layers.

FIG. Al1 represents the board as it comes off the machine shoWn in FIG. l0, and FIG. 12 shows the board comprising sheets of plain paper 62.

What I claim is:

1. A device for corrugating paper, comprising two parallel upper side frames, two lower side frames parallel to said upper side frames, a plurality of rollers mounted upon said upper side frames, a plurality of rollers mounted upon said lower side fra-mes, the rollers mounted upon said upper side frames being located directly above the rollers mounted upon said lower side frames to form pairs of cooperating rollers extending in spaced relation and in parallel planes between an inlet end of said side frames and an outlet end thereof, each of the rollers belonging to the pair of rollers located closest to said inlet end having three centrally located adjacent circumferential grooves, the grooves of one roller being located directly above the grooves of the other roller, each of the rollers belonging to a pair of rollers located closer to said outlet end than a preceding pair of rollers having a number of grooves which is twice the number of grooves of said preceding pair of rollers, the grooves of all of saidrollers being uniformly disposed and located in parallel planes, a -power roller carried by said upper side frames at said outlet end, another power roller carried by said lower side frames at said outlet end and below the iirst-mentioned power roller, said power rollers having grooves alined with fthe grooves of said rollers, and endless belts extending between said rollers and said power rollers, each of said belts extending circumferentially over a separate groove of one of said power rollers and a separate groove of one of said rollers, the belt extending circumferentially over a groove of one of said rollers being located opposite a free groove of the other roller belonging to the same pair of rollers, said free groove being devoid of engagement with a belt, belts extending over grooves of the same pair of rollers being located one next to each other to form a corrugating space for a paper sheet, whereby the corrugation of said sheet in said corrugating spaces proceeds gradually and uniformly from said inlet end toward said outlet end.

2. A device in accordance with claim 1, wherein the belts have trapezoidall'y shaped portions fitting in the roller grooves and portions projecting from the roller grooves and having a shape corresponding to the shape of the corrugations to be imparted upon the paper.

3. A device in accordance with claim 2, wherein said belts have intermediate portions of rectangular cross-section, the intermediate portion of each belt abutting intermediate portions of adjoining belts, whereby a continuous mat is formed.

References Cited in the file of this patent UNITED STATES PATENTS 762,033 Ferres June 7, `1904 1,058,856 Gibbs Apr. 15, 1913 1,906,342 Smith May 2, 1933 2,182,720 Cannard Dec. 5, 1939 2,236,932 Arentsen Apr. 1, 1941 2,649,888 Fay Aug. 25, 1953 2,710,043 Hubmeier June 7, 1955 FOREIGN PATENTS 19,056 Great Britain 1914 506,599 Germany Sept. 5, 1930 

1. A DEVICE FOR CORRUGATING PAPER, COMPRISING TWO PARALLEL UPPER SIDE FRAMES, TWO LOWER SIDE FRAMES PARALLEL TO SAID UPPER SIDE FRAMES, A PLURALITY OF ROLLERS MOUNTED UPON SAID UPPER SIDE FRAMES, A PLURALITY OF ROLLERS MOUNTED UPON SAID LOWER SIDE FRAMES, THE ROLLERS MOUNTED UPON SAID UPPER SIDE FRAMES BEING LOCATED DIRECTLY ABOVE THE ROLLERS MOUNTED UPON SAID LOWER SIDE FRAMES TO FORM PAIRS OF COOPERATING ROLLERS EXTENDING IN SPACED RELATION AND IN PARALLEL PLANES BETWEEN AN INLET END OF SAID SIDE FRAMES AND AN OUTLET END THEREOF, EACH OF THE ROLLERS BELONGING TO THE PAIR OF ROLLERS LOCATED CLOSEST TO SAID INLET END HAVING THREE CENTRALLY LOCATED ADJACENT CIRCUMFERENTIAL GROOVES, THE GROOVES OF ONE ROLLER BEING LOCATED DIRECTLY ABOVE THE GROOVES OF THE OTHER ROLLER, EACH OF THE ROLLERS BELONGING TO A PAIR OF ROLLERS LOCATED CLOSER TO SAID OUTLET END THAN A PRECEDING PAIR OF ROLLERS HAVING A NUMBER OF GROOVES WHICH IS TWICE THE NUMBER OF GROOVES OF SAID PRECEDING PAIR OF ROLLERS, THE GROOVES OF ALL SAID ROLLERS BEING UNIFORMLY DISPOSED AND LO- 